Dynamic vibrations mechanically produced can be damped by interposing an elastomer between components. Typical vibration damping devices are shown in U.S. Pat. Nos. 3,031,034; 3,077,244; 3,085,658; 3,388,772; 3,826,339; 4,133,157 and 4,361,214. In these patents a diversity of arrangements are disclosed wherein an elastomer is bonded or interposed between support and inertia members to absorb and dissipate vibrations.
In the attachment of elastomers to damper components, it is common to bond the elastomer to the support and inertia members, which usually are of metal, by adhesives, heat treatments, vulcanizing, or the like. As the dynamic character of the damper imposes considerable stress on the damper components, difficulty has been encountered in successfully using conventional bonding and vulcanizing techniques, and the failure of conventionally constructed vibration dampers is common, and extended life cycles are difficult to achieve.
The assignee has utilized the elastomeric forces within an elastomer to maintain the assembly of rotary vibration dampers as used with internal combustion engine crankshafts wherein the elastomer is installed by a tensioning or stretching of the elastomer during assembly and the resultant frictional forces occurring due to the tendency for the elastomer to return to its normal state and dimensions frictionally maintains the assembled components. Examples of this type of device are shown in the assignee's U.S. Pat. Nos. 3,670,593 and 2,882,747. However, the assembly procedures shown in the aforementioned patents have not been previously utilized with dynamic linear dampers, and it is an object of the invention to provide a dynamic linear vibration damper of an economical construction which has an extended operational life and yet is economical to produce and assemble.
A further object of the invention is to provide a dynamic linear vibration damper utilizing a support member, an inertia member and an elastomer wherein the internal forces within the elastomer are utilized to maintain the assembly of the components, and bonding or vulcanizing techniques are not required.
Yet another object of the invention is to provide a dynamic linear vibration damper capable of damping a wide range of vibration frequencies, and wherein the damper is of such configuration and operation as to be suitable for a wide variety of applications.
In the practice of the invention, a support is mounted upon the members to be damped. The support is preferably formed of sheet metal and is of an economical construction, as are the other components of the damper. The support includes at least one planar extension having a free end receivable within an opening formed in an inertia or mass member.
The inertia member usually consists of a relatively heavy material, such as metal, and may be cast, stamped, or otherwise fabricated. The inertia member includes an opening receiving the support extension free end and parallel spaced sides defining the opening are in spaced relationship to the support extension wherein an elastomer is interposed between the extension and the opening sides so that the inertia member is mounted on the support by the elastomer.
The assembly of the support extension, inertia member and elastomer is achieved by internal forces within the elastomer producing high frictional engagement between the three components. To achieve this relationship the elastomer is inserted into the mass member opening while under tension such that the resiliency of the elastomer tending to restore the elastomeric material to its normal condition produces high frictional forces against the confining surfaces of the opening and upon the support extension. The assembly of the elastomer within the opening is readily achieved by forcing the elastomer into the mass member openings by the free end of the extension wherein the elastomer is automatically stretched and tensioned as it is inserted into the opening.
For safety purposes, an abutment, in the form of a pin, is mounted upon the extension free end to prevent withdrawal of the extension from the opening in the event of failure of the elastomer to maintain the assembly.
With the practice of the invention, an effective dynamic linear vibration damper is readily assembled from economically fabricated components capable of an effective and long operative life.